European Patent Application No. 80 40 1369, Publication Number 027,752, published Apr. 29, 1981, discloses certain substituted 7-(3-amino-1-pyrrolidnyl)-1-ethyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyri dine-3-carboxylic acids having the general formula: ##STR1## The compounds are disclosed to have antibacterial activity.